diff --git a/src/Mod/Drawing/App/DrawingExport.cpp b/src/Mod/Drawing/App/DrawingExport.cpp
index 1f654caf60..516458e917 100644
--- a/src/Mod/Drawing/App/DrawingExport.cpp
+++ b/src/Mod/Drawing/App/DrawingExport.cpp
@@ -207,9 +207,10 @@ void SVGOutput::printCircle(const BRepAdaptor_Curve& c, std::ostream& out)
     }
     // arc of circle
     else {
+        using std::numbers::pi;
         // See also https://developer.mozilla.org/en/SVG/Tutorial/Paths
-        char xar = '0';                         // x-axis-rotation
-        char las = (l - f > D_PI) ? '1' : '0';  // large-arc-flag
+        char xar = '0';                       // x-axis-rotation
+        char las = (l - f > pi) ? '1' : '0';  // large-arc-flag
         char swp = (a < 0) ? '1' : '0';  // sweep-flag, i.e. clockwise (0) or counter-clockwise (1)
         out << "<path d=\"M" << s.X() << " " << s.Y() << " A" << r << " " << r << " " << xar << " "
             << las << " " << swp << " " << e.X() << " " << e.Y() << "\" />";
@@ -255,7 +256,8 @@ void SVGOutput::printEllipse(const BRepAdaptor_Curve& c, int id, std::ostream& o
     }
     // arc of ellipse
     else {
-        char las = (l - f > D_PI) ? '1' : '0';  // large-arc-flag
+        using std::numbers::pi;
+        char las = (l - f > pi) ? '1' : '0';  // large-arc-flag
         char swp = (a < 0) ? '1' : '0';  // sweep-flag, i.e. clockwise (0) or counter-clockwise (1)
         out << "<path d=\"M" << s.X() << " " << s.Y() << " A" << r1 << " " << r2 << " " << angle
             << " " << las << " " << swp << " " << e.X() << " " << e.Y() << "\" />" << std::endl;
@@ -460,6 +462,8 @@ void DXFOutput::printHeader(std::ostream& out)
 
 void DXFOutput::printCircle(const BRepAdaptor_Curve& c, std::ostream& out)
 {
+    using std::numbers::pi;
+
     gp_Circ circ = c.Circle();
     const gp_Pnt& p = circ.Location();
     double r = circ.Radius();
@@ -502,8 +506,8 @@ void DXFOutput::printCircle(const BRepAdaptor_Curve& c, std::ostream& out)
         double bx = e.X() - p.X();
         double by = e.Y() - p.Y();
 
-        double start_angle = atan2(ay, ax) * 180 / D_PI;
-        double end_angle = atan2(by, bx) * 180 / D_PI;
+        double start_angle = atan2(ay, ax) * 180 / pi;
+        double end_angle = atan2(by, bx) * 180 / pi;
 
         if (a > 0) {
             double temp = start_angle;
diff --git a/src/Mod/Drawing/Gui/TaskOrthoViews.cpp b/src/Mod/Drawing/Gui/TaskOrthoViews.cpp
index 98d8a2897f..319dbcb186 100644
--- a/src/Mod/Drawing/Gui/TaskOrthoViews.cpp
+++ b/src/Mod/Drawing/Gui/TaskOrthoViews.cpp
@@ -256,7 +256,7 @@ void orthoview::set_projection(const gp_Ax2& cs)
     // angle between desired projection and actual projection
     float rotation = X_dir.Angle(actual_X);
 
-    if (rotation != 0 && abs(M_PI - rotation) > 0.05) {
+    if (rotation != 0 && abs(std::numbers::pi - rotation) > 0.05) {
         if (!Z_dir.IsEqual(actual_X.Crossed(X_dir), 0.05)) {
             rotation = -rotation;
         }
@@ -266,7 +266,7 @@ void orthoview::set_projection(const gp_Ax2& cs)
 
     // this_view->Direction.setValue(Z_dir.X(), Z_dir.Y(), Z_dir.Z());
     this_view->Direction.setValue(x, y, z);
-    this_view->Rotation.setValue(180 * rotation / M_PI);
+    this_view->Rotation.setValue(180 * rotation / std::numbers::pi);
 }
 
 ///////////////////////////////////////////////////////////////////////////////////////////////
@@ -613,8 +613,8 @@ void OrthoViews::set_orientation(int index)  // set orientation of single view
             dir = primary.XDirection();
             n = -views[index]->rel_y;
         }
-
-        rotation = n * rotate_coeff * M_PI / 2;  // rotate_coeff is -1 or 1 for 1st or 3rd angle
+        // rotate_coeff is -1 or 1 for 1st or 3rd angle
+        rotation = n * rotate_coeff * std::numbers::pi / 2;
         cs = primary.Rotated(gp_Ax1(gp_Pnt(0, 0, 0), dir), rotation);
         views[index]->set_projection(cs);
     }
@@ -780,7 +780,7 @@ void OrthoViews::set_Axo(int rel_x,
         rotations[1] = -0.6156624905260762;
     }
     else {
-        rotations[0] = 1.3088876392502007 - M_PI / 2;
+        rotations[0] = 1.3088876392502007 - std::numbers::pi / 2;
         rotations[1] = -0.6156624905260762;
     }